flask数据库, cookies, session

2019-11-16

Flask的SQLAlchemy拓展

安装Flask的SQLAlchemy拓展包

先进入虚拟环境
pip install flask-sqlalchemy

使用到的用户模型

用户：
账号名称
账号密码

为config添加数据库路径

SQLALCHEMY_DATABASE_URI = 'sqlite:///flaskproject.sqlite3'
SQLALCHEMY_TRACK_MODIFICATIONS = False

创建 models.py 文件

from flask_sqlalchemy import SQLAlchemy
from run import app

db = SQLAlchemy(app)
class User(db.Model):
    __tablename__ = 'user'
    id = db.Column(db.Integer, primary_key = True)
    username = db.Column(db.String(50))
    password = db.Column(db.String(100))

    def __init__(self, name, psw):
        self.username = name
        self.password = psw

    def __repr__(self):
        return 'User' + self.username

创建用于创建数据库的 createDB.py

该文件与run.py在同一目录下
-account
-run.py
-createDB.py

from account import models # 导入模型

models.db.create_all() # 创建数据库

运行createDB.py

python createDB.py
在account文件夹中看到flaskproject.sqlite3就说明数据库创建成功了

修改注册表单 views.py

from models import db,User

@app.route('/register', methods = ['GET', 'POST'])
def register():
    title = '注册'
    if request.method == 'GET':
        return render_template("register.html", title = title)
    else:
        username = request.form["USERNAME"]
        password = request.form["PASSWORD"]
        confirm = request.form["CONFIRM"]
        if password == confirm:
            try:
                user = User(username, password)
                db.session.add(user)
                db.session.commit()
                message = '注册成功'
            except:
                message = '用户已存在'
        else:
            message = '密码不一致'
        return render_template("message.html", title = title, message = message)

表单简化

将注册部分变成User类的一个方法
views.py

def register():
    title = '注册'
    if request.method == 'GET':
        return render_template("register.html", title = title)
    else:
        username = request.form["USERNAME"]
        password = request.form["PASSWORD"]
        confirm = request.form["CONFIRM"]
        if password == confirm:
            message = User.adduser(username, password)
        else:
            message = '密码不一致'
        return render_template("message.html", title = title, message = message)

在models.py 为 User 添加 adduser方法

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(50), unique=True)
    password = db.Column(db.String(100))

    def adduser(username, password):
        try:
            user = User(username, password)
            db.session.add(user)
            db.session.commit()
            return '注册成功'
        except:
            return '用户已存在'

为 User 添加checkPassword 方法：

def checkPassword(username, password):
        user = User.query.filter_by(username = username).first()
        if user:
            if user.password == password:
            	return '密码正确'
            else:
            	return '密码错误'
        else:
        	return '用户不存在'

修改登陆表单

@app.route('/login')
def login():
    title = '登陆页面'
    if 'USERNAME' in request.args:
        username = request.args.get('USERNAME')
        password = request.args.get('PASSWORD')
        if username != '' and password != '':
            message = User.checkPassword(username, password)
        else:
            message = '请输入用户名或密码'
        return render_template("message.html", title = title, message = message)
    return render_template("login.html", title = title)

为用户登陆设置cookie

修改注册和登陆表单

# 从flask导入make_response
from flask import make_response

# 修改注册表单
# 将注册成功后的返回值修改为
	if message == '注册成功':
        response = make_response(render_template("message.html", title = title, message = message))
        response.set_cookie('user', username, 60 * 5)
        return response
    else:
        return render_template("message.html", title = title, message = message)

# 修改登陆表单
# 修改登陆后的返回
@app.route('/login')
def login():
    title = '登陆页面'
    if 'USERNAME' in request.args:
        username = request.args.get('USERNAME')
        password = request.args.get('PASSWORD')
        if username != '' and password != '':
            message = User.checkPassword(username, password)
        else:
            message = '请输入用户名或密码'
        if message == '密码正确':
            response = make_response(render_template("message.html", title = title, message = message))
            response.set_cookie('user', username, 60 * 5)
            return response
        else:
            return render_template("message.html", title = title, message = message)
    return render_template("login.html", title = title)

添加登出视图

@app.route('/logout')
def logout():
    title = '登出'
    message = '登出成功'
    response = make_response(render_template("message.html", title = title, message = message))
    response.delete_cookie('user')
    return response

修改base.html

<a href="/">主页</a>
	{% if 'user' in request.cookies %}
		<label>Hello, {{ request.cookies.get('user') }}</label>
		<a href="/logout">登出</a>
	{% else %}
		<a href="/register">注册</a>
		<a href="/login">登陆</a>
	{% endif %}
	{% block content %}
	{% endblock %}

使用session

cookie明文存储可以轻易的模拟其他用户
而session是加密后的cookie比较安全

# 导入 session
from flask import session

# 设置session
session['user'] = 'jkle'

# session部分参数设置
# 开启session持久化存储
session.permanent = True
# 设置session存活时间为1分钟  如果不给出存活时间 则默认为1个月
app.permanent_session_lifetime = timedelta(seconds=60) 

# 获取session
session.get('user')

# 删除session
# 删除key为uid的session值
session.pop('uid')
# 删除所有session
session.clear()

将cookie相关的设置替换为session即可。